Industrial sewing machines and embroidering machines must be operated by sewing machine operators, plant mechanics and service personnel. Not all input and operating functions usually need to be accessible by the different persons. Certain functions were therefore made accessible to only certain persons, and distinctions can be made concerning authorized access between access via a code number, access via a key and free access.
The access of the different groups of persons to the different modes of operation of a machine is frequently set at the time of the shipping of a sewing machine. However, such a setting has the drawback that it does not take into account the greatly different work processes in different plants, because, e.g., the sewing machine operator is to use only the basic modes of operation in one plant, while the sewing machine operator shall also perform additional settings and programming of the machine in another plant.
A sewing machine with an electronic control device containing a microcomputer, in which the control device and consequently the microcomputer are connected to at least one input means for entering the actually desired mode of operation of the sewing machine (in the form of control codes), has already been known from DE 40 00 765 A1. The input means also includes, among other things, a keyboard.
A process and a device for checking the access authorization between a chip card and a terminal unit, in which a plurality of authorization codes are stored in corresponding memories in both the chip card and the terminal unit, have been known from DE 43 06 819 C2.
A relatively complicated process for determining the access authorization of the user of a computer of a networked computer system has been known from DE 44 43 339 A1. The user of the computer in question identifies himself by means of his computer against an identification server via his name, an identifier for the type of the access method (e.g., a password or a chip card) and a coded sequence of his personal data and a key for a coding process.
Furthermore, a locking system, in which data can be inductively transmitted between a code module and a lock module, has been known from DE 44 22 081 C2.